From: Srivatsa S. Bhat (VMware) srivatsa@csail.mit.edu
commit fc64e4ad80d4b72efce116f87b3174f0b7196f8e upstream.
max_latency is intended to record the maximum ever observed hardware latency, which may occur in either part of the loop (inner/outer). So we need to also consider the outer-loop sample when updating max_latency.
Link: http://lkml.kernel.org/r/157073345463.17189.18124025522664682811.stgit@sriva...
Fixes: e7c15cd8a113 ("tracing: Added hardware latency tracer") Cc: stable@vger.kernel.org Signed-off-by: Srivatsa S. Bhat (VMware) srivatsa@csail.mit.edu Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/trace/trace_hwlat.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/kernel/trace/trace_hwlat.c +++ b/kernel/trace/trace_hwlat.c @@ -257,6 +257,8 @@ static int get_sample(void) /* Keep a running maximum ever recorded hardware latency */ if (sample > tr->max_latency) tr->max_latency = sample; + if (outer_sample > tr->max_latency) + tr->max_latency = outer_sample; }
out: